The image will always degrade with higher magnification. It's normal. A better eyepiece will help (something in the $300 range) but it won't be all that much with an 8" scope. Don't be fooled by claims of the 50x aperteur rule. That's only for the best of scopes on the best of nights and mainly for the planets and moon. Most nights if you can get half that, it's pretty good. Of course a bigger scope with a longer focal length will focus better at higher magnification, but the very best is a good APO refractor. How high magnification you can use varies from night to night based on the sky conditions. In general, I say the highest magnification you can use is what looks good in the eyepiece that night. I have the 12" LX200 which is f/10. Most nights I use the 22mm eyepiece at 138x and the 40MM at 76x and the focus is great. It starts to degrade with the 14mm at 218x. Some nights is real sharp at 218x and I can get a little more. But other nights I put the 14MM away and don't even try it again. Your scope, at f/5, was not designed for real high magnification. I'd get something in the 17MM range for deep sky. the 9.7 should be good for the planets. If you want more, I'd get a smaller eyepiece alone and forget about the barlow. Some people sware by them, I don't like them. A smaller eyepiece will do the same thing and lets face it, how often do you use it with a bigger eyepiece. I recommend the Teleview Radians for short focal length eyepieces. They all have 20mm eye relief which is great for eyeglass warers. They run about $230 and are worth every penny
That's it;
BOB SAL

• Thanks, but... - dude31 - June 28, 2002 - 17:10 UTC
  • Barlows, my opinion - bobsal - June 28, 2002 - 19:27 UTC
    • Why not use the barlow?? - dude31 - June 28, 2002 - 21:20 UTC
      • Re: Why not use a Barlow? - jkoptic - June 28, 2002 - 22:30 UTC
        • Thank you - dude31 - June 29, 2002 - 05:25 UTC